CVE-2020-2174 in AWSEB Deployment Plugin
Summary
by MITRE
Jenkins AWSEB Deployment Plugin 0.3.19 and earlier does not escape various values printed as part of form validation output, resulting in a reflected cross-site scripting vulnerability.
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Analysis
by VulDB Data Team • 04/08/2020
The Jenkins AWSEB Deployment Plugin vulnerability CVE-2020-2174 represents a critical cross-site scripting flaw that emerged in versions 0.3.19 and earlier of the AWS Elastic Beanstalk deployment plugin. This vulnerability stems from insufficient input sanitization within the plugin's form validation mechanisms, where user-supplied data is directly incorporated into HTML output without proper escaping or encoding. The flaw specifically affects the plugin's handling of various form fields during deployment configuration processes, creating an avenue for malicious actors to inject arbitrary JavaScript code into web interfaces. The vulnerability manifests when Jenkins administrators or users interact with the plugin's configuration forms, particularly during AWS Elastic Beanstalk deployment operations where parameters such as application names, environment names, and region identifiers are processed.
The technical implementation of this vulnerability aligns with CWE-79, which describes cross-site scripting flaws resulting from improper output encoding. The plugin fails to properly escape special characters including angle brackets, quotes, and script tags when rendering form validation messages, allowing attackers to inject malicious payloads that execute in the context of the victim's browser. This reflected XSS vulnerability occurs because the plugin does not sanitize user inputs before displaying them in web responses, making it particularly dangerous in environments where multiple users interact with the Jenkins instance. The reflected nature of the vulnerability means that malicious payloads must be delivered through crafted URLs or form submissions, making it exploitable via social engineering attacks or when users are tricked into clicking malicious links within the Jenkins interface.
The operational impact of CVE-2020-2174 extends beyond simple data theft, as it enables attackers to perform session hijacking, deface web interfaces, and potentially escalate privileges within the Jenkins environment. An attacker could craft malicious form inputs that, when validated and displayed, would execute JavaScript code in the browser of any user who views the affected form or validation messages. This could lead to unauthorized access to Jenkins build configurations, credentials stored within the system, or even allow attackers to execute arbitrary code on the Jenkins server if additional vulnerabilities exist. The vulnerability particularly affects organizations that rely heavily on Jenkins for CI/CD pipelines, as compromised Jenkins instances can provide attackers with access to source code repositories, build artifacts, and deployment credentials. The attack surface is broadened by the fact that Jenkins administrators frequently interact with plugin interfaces, making this vulnerability particularly dangerous in enterprise environments where Jenkins serves as a central automation platform.
Mitigation strategies for CVE-2020-2174 should prioritize immediate plugin version updates to 0.3.20 or later, where the XSS vulnerability has been addressed through proper input sanitization and output escaping mechanisms. Organizations should implement comprehensive input validation across all Jenkins plugins and ensure that all user-supplied data is properly escaped before rendering in web contexts. Security configurations should include enabling Jenkins security features such as CSRF protection and implementing proper access controls to limit who can install or configure plugins. Network-level protections including web application firewalls and content security policies can provide additional defense-in-depth measures. Regular security auditing of Jenkins plugins and continuous monitoring for similar vulnerabilities should be established as part of organizational security practices. The vulnerability demonstrates the importance of input sanitization in web applications and aligns with ATT&CK technique T1211 for lateral movement through compromised Jenkins instances, highlighting the need for comprehensive security hygiene practices in continuous integration environments.